refresh_interceptor 0.1.0

Reusable Dio interceptor for attaching access tokens, refreshing them once, and retrying failed requests.

0.1.0

• Initial release with token injection, single-flight refresh, request retry, refresh-token rotation, and session-expiry handling.
• Simplified setup with RefreshInterceptor.attachTo and attachToAll.
• Added shared refresh state across multiple Dio clients.
• Added TokenStoreAdapter for existing storage method tear-offs.
• Added automatic new-session detection and safe duplicate attachment.
• Preserved non-auth errors returned by retried requests.